Such connecting devices are known, for example, from EP 0 176 663, DE 4 224 575 A1, DE 36 20 005 C1 and DE 44 12 431 C1. The known connecting device has two parts, which comprise a plurality of individual components in particular made of different materials. These parts are connected to one another by a thread. One part forms a supporting part and can be connected to a first component. The second part, which forms the spacer part, is screwed to the support part by a left-handed thread and forms an end surface which is spaced apart from the second component. As the connecting screw is fitted into the spacer part, the resilient elements come into frictional engagement against the screw shank. If the screw is now rotated, then the spacer part moves with screwing action out of the supporting part because it is carried along with a friction fit by the screw shank. The supporting part moves with screwing action into the abutment position in relation to the second component. Thereafter, the frictional force by which resilient elements engage against the lateral surface of the screw shank is
The invention relates to a device for the bracing connection of spaced-apart components by means of a connecting screw, comprising a supporting part, which can be secured on the first component by means of fastening elements, and a spacer part, which can be displaced axially in relation to the supporting part by virtue of rotation and, as the connecting screw, fitted into an opening of the spacer part, is screwed in, is carried along, as a result of friction-fitting engagement of the lateral surface of the screw shank against resilient elements projecting into the opening, until it strikes against the second component. less than the spacing force or the thread friction between the thread turns of the spacer part and supporting part, so that the screw can be screwed further through the opening of the two parts screwed one inside the other until it engages in the mating thread, associated with the first or the second component, in order to brace the two components with one another, these otherwise being supported against one another as a result of the two parts of the device moved into the spaced-apart position. A variant of the fastening is also possible, in which case the connecting screw may first of all be fitted through the opening of the two parts of the device until it reaches the mating thread. As the connecting screw is screwed into the mating thread, the two components of the device then move out with screwing action, carried along with a friction fit, until the spacer part passes into the abutment position in relation to the second component. Two variants are possible. In the first variant, the spacer part is displaced into the abutment position counter to the screwing-in direction. In the second variant, the spacer part is carried along with a friction fit by the screw rotation, in the same direction as the latter.
Accordingly the invention provides that both the supporting part and spacer part are formed in one piece as threaded bushings. In this case, they may consist of plastics or of metal. They may be produced by deep drawing. The device is now produced from two blanks. Both blanks are present as flat elements, in particular metal sheets. These are first of all deep drawn. The fastening elements and the resilient elements are each formed from the metal sheet, preferably by being cut out. The cutting out may take place before or after the deep drawing. In a preferred configuration of the invention, in each case one thread is formed on the walls of the threaded bushings. The leads and cross-sectional shapes of the turns of the threads are such that the two threaded bushings can be screwed one inside the other. It is preferable for the threaded bushing of the spacer part to be screwed into the threaded bushing of the supporting part. It has proven advantageous in production terms if the threads are rolled on. Both the supporting part and the spacer part preferably have, on a bushing border, an outwardly projecting annular collar. This annular collar forms the abutment surfaces by means of which, on the one hand, the support part and, on the other hand, the spacer part interact with the associated component, in particular can be fastened thereon. The fastening elements are tongues which are cut out of the annular collar preferably from the outside. These tongues project on that side of the annular collar which is located opposite the bushing, and can be clipped into a fastening opening. The resilient elements are cut out of an, in particular, thread-free bushing section adjacent to the annular collar. The flanks of the thread turns are preferably at an angle of 60xc2x0 in relation to one another. In a development of the invention, it may be provided that the threaded sections of the two components are sheathed in plastics and/or lined with plastics. Furthermore, it is possible for the two parts, in particular formed from a single piece of material, the supporting part and spacer part, to consist entirely of sheet metal or of plastics. It may further be provided that the fastening element is formed as a clip. In this case, it is provided, in particular, that a counter plate runs parallel to the collar, the counter plate being connected integrally to the collar and forming a U-shaped angled portion. In alignment with the threaded bushings, this counter plate forms a through-passage opening for the connecting screw. It may further be provided that a stop lug is integrally formed on one of the two threaded bushings. This may likewise be in the form of a tongue. This stop lug, together with a counter stop of the other part, forms a rotary limit stop. The counter stop may be formed by a cut-out section of a collar.
It is further provided that the two threaded bushings are formed by injection moulding. The injection mouldings here have, in particular, annular collars. In a preferred configuration of the invention, the threaded bushings have smooth-walled surfaces on their side directed away from the threads. It may further be provided that the internal thread is interrupted in certain regions in the circumferential direction. It is preferably possible to provide four thread-free zones distributed uniformly over the circumference.
The invention advantageously comprises just two single-material parts, i.e. parts which are not themselves assembled from different elements. Each part is produced in a single piece.